The Hadron plugin is your ultimate granular synthesis tool. In fact it is such a complete implementation of granular synthesis we’ve renamed the technique to particle synthesis. The plugin is of course free and open source.

Fathom is a modular software synthesizer plugin that features a wide variety of audio components, advanced modulation, detuning and distortion capabilities as well as the ability to
draw your own waveforms and import single cycle waveforms from outside sources.

Drift is a multi-effects processor based on two independent Lorenz chaos oscillators. These systems are used by scientists to model convection in liquids and gases: they produce chaotically fluctuating, never-repeating signals that are mutually correlated.